package com.googlecode.grima.util;

import java.io.IOException;
import javax.servlet.*;
import javax.servlet.http.*;

public class DisableUrlSessionFilter implements Filter {

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {

		if (!(request instanceof HttpServletRequest)) {
			chain.doFilter(request, response);
			return;
		}

		HttpServletRequest httpRequest = (HttpServletRequest) request;
		HttpServletResponse httpResponse = (HttpServletResponse) response;

		if (httpRequest.isRequestedSessionIdFromURL()) {
			HttpSession session = httpRequest.getSession();
			if (session != null)
				session.invalidate();
		}

		HttpServletResponseWrapper wrappedResponse = new HttpServletResponseWrapper(
				httpResponse) {
			@Override
			public String encodeRedirectUrl(String url) {
				return url;
			}

			@Override
			public String encodeRedirectURL(String url) {
				return url;
			}

			@Override
			public String encodeUrl(String url) {
				return url;
			}

			@Override
			public String encodeURL(String url) {
				return url;
			}
		};

		chain.doFilter(request, wrappedResponse);
	}

	public void init(FilterConfig config) throws ServletException {
	}

	public void destroy() {
	}

}
